Index: src/Deltares.DSoilModel.Forms.Tests/ControlTester.cs
===================================================================
diff -u -r329 -r343
--- src/Deltares.DSoilModel.Forms.Tests/ControlTester.cs	(.../ControlTester.cs)	(revision 329)
+++ src/Deltares.DSoilModel.Forms.Tests/ControlTester.cs	(.../ControlTester.cs)	(revision 343)
@@ -13,6 +13,9 @@
 {
     public class ControlTester
     {
+        private readonly string CannotFindControlFormatString = "Cannot find {0} : {1} control.";
+        private readonly string InitialValueMismatchString = "Initial value mismatch";
+        private readonly string ObjectDidntReceivedValueString = "The object didn't receive the value";
         private KnownUnits knownUnits;
         private bool oldBypass;
         private LanguageType oldLanguage;
@@ -65,9 +68,9 @@
             bool isEnabledExpected)
         {
             var edit = GetPrivateField(parentControl, spinEditName) as Control;
-            Assert.IsNotNull(edit);
-            Assert.AreEqual(isVisibleExpected, edit.Visible);
-            Assert.AreEqual(isEnabledExpected, edit.Enabled);
+            Assert.IsNotNull(edit, CannotFindControlFormatString, spinEditName, "<unknown>");
+            Assert.AreEqual(isVisibleExpected, edit.Visible, spinEditName + ": Visible-check failed");
+            Assert.AreEqual(isEnabledExpected, edit.Enabled, spinEditName + ": Enabled-check failed");
         }
 
         protected void TestSpinEditVisibleEnabledValue<T>(IPropertyControl parentControl, string spinEditName, bool isVisibleExpected, bool isEnabledExpected, T target, Expression<Func<T, double>> outExpr, double? valueToTestWith = null)
@@ -76,57 +79,56 @@
             if (isVisibleExpected)
             {
                 var edit = GetPrivateField(parentControl, spinEditName) as SpinEdit;
-                Assert.IsNotNull(edit);
+                Assert.IsNotNull(edit, CannotFindControlFormatString, spinEditName, "SpinEdit");
 
                 var initialValue = GetValue(target, outExpr);
-                Assert.AreEqual(initialValue, edit.Value);
+                Assert.AreEqual(initialValue, edit.Value, InitialValueMismatchString);
 
-                if (valueToTestWith == null)
+                if (valueToTestWith != null)
                 {
-                    return;
+                    edit.EditValue = valueToTestWith;
+                    Assert.AreEqual(valueToTestWith, GetValue(target, outExpr), ObjectDidntReceivedValueString);
+                    edit.EditValue = initialValue; // restoring initial value - it might be still useful
                 }
-
-                edit.EditValue = valueToTestWith;
-                Assert.AreEqual(valueToTestWith, GetValue(target, outExpr));
-                edit.EditValue = initialValue; // restoring initial value - it might be still useful
             }
         }
 
         protected void TestTextEditVisibleEnabledValue<T>(IPropertyControl parentControl, string textEditName,
             bool isVisibleExpected, bool isEnabledExpected, T target, Expression<Func<T, string>> outExpr, string newValue = null)
         {
             TestControlVisibleEnabled(parentControl, textEditName, isVisibleExpected, isEnabledExpected);
-            var edit = GetPrivateField(parentControl, textEditName) as TextEdit;
-            Assert.IsNotNull(edit);
+            if (isVisibleExpected)
+            {
+                var edit = GetPrivateField(parentControl, textEditName) as TextEdit;
+                Assert.IsNotNull(edit, CannotFindControlFormatString, textEditName, "TextEdit");
 
-            var initialValue = GetValue(target, outExpr);
-            Assert.AreEqual(initialValue, edit.EditValue);
+                var initialValue = GetValue(target, outExpr);
+                Assert.AreEqual(initialValue, edit.EditValue, InitialValueMismatchString);
 
-            if (newValue == null)
-            {
-                return;
+                if (newValue != null)
+                {
+                    edit.EditValue = newValue;
+                    Assert.AreEqual(newValue, GetValue(target, outExpr), ObjectDidntReceivedValueString);
+                    edit.EditValue = initialValue; // restoring initial value - it might be still useful
+                }
             }
-
-            edit.EditValue = newValue;
-            Assert.AreEqual(newValue, GetValue(target, outExpr));
-            edit.EditValue = initialValue; // restoring initial value - it might be still useful
         }
 
         protected void TestLabelControlVisibleValue(IPropertyControl parentControl, string labelControlName, bool isVisibleExpected, string labelTextExpected)
         {
             TestControlVisibleEnabled(parentControl, labelControlName, isVisibleExpected, true); // labels are always enabled in DSL projects
             var labelControl = GetPrivateField(parentControl, labelControlName) as LabelControl;
-            Assert.IsNotNull(labelControl);
-            Assert.AreEqual(labelTextExpected, labelControl.Text);
+            Assert.IsNotNull(labelControl, CannotFindControlFormatString, labelControlName, "LabelControl");
+            Assert.AreEqual(labelTextExpected, labelControl.Text, InitialValueMismatchString);
         }
 
         protected void TestGridVisibleEnabledSize(IPropertyControl parentControl, string gridName, bool isVisibleExpected, bool isEnabledExpected, int rowCount, int colCount)
         {
             TestControlVisibleEnabled(parentControl, gridName, isVisibleExpected, isEnabledExpected);
             var gridControl = GetPrivateField(parentControl, gridName) as GridViewControl;
-            Assert.IsNotNull(gridControl);
-            Assert.AreEqual(rowCount, gridControl.gridView1.RowCount);
-            Assert.AreEqual(colCount, gridControl.gridView1.Columns.Count);
+            Assert.IsNotNull(gridControl, CannotFindControlFormatString, gridName, "GridViewControl");
+            Assert.AreEqual(rowCount, gridControl.gridView1.RowCount, "Row count mismatch");
+            Assert.AreEqual(colCount, gridControl.gridView1.Columns.Count, "Columns count mismatch");
         }
     }
 }
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